Online social media services, such as social networking systems and content sharing platforms, provide an environment for discussing time-based media (TBM) content. Accounts may discuss TBM content posted by other accounts through social media content items (SMCIs). These SMCIs may be indirectly associated with TBM content about news events, television shows, movies, sporting events, or concerts. However, entities that create and distribute TBM content may not know which accounts are interested in the TBM content. Content distributors and promoters may reach a target audience indirectly through broadcasting, but they lack a mechanism to send supplemental TBM content to the target audience directly.